Excellent find that page! Confirms my gut feeling that CFLS have the worst spectrum, and LEDS were immensely better.
I hated CFLs. I tried to love them, but I ended up hating them. They were unutterable crap. I expected LEDS to be little better, but now I won't buy anything else. There are issues with cooling, drivers and so on, but when they work they are just perfect for me
Fun!
Spectral Power Distribution, LEDs have a lot of near visble blue in them, whatever colour they are.
Metal halides and fluros have a blue peak much lower down.
Question is what effect does the high blue content have.
With respect, bollox. ;-)
Now try doing the same today using GLS and direct replacements for GLS.
You can do quite an easy test by looking at a paint colour chart under both decent tungsten - ie halogen - and LED. It can be revealing.
As spectacle wearing drivers will notice, it is noticeable that the blue component is strong when looking at white LED daylight running lights of a following car in your side-mirrors ...
Utter total BOLLOCKS
A red LED has almost NO emission in the blue part of the spectrum whatsoever. Neither does an orange or yellow.
Greens have a little, but you need a BLUE LED to actually start to have any appreciable 'whiteness' - let lone 'blueness' in the spectrum.
And LED emission is not, like fluorescents, single spectral lines that excite phosphors, its broad spectral lines that excite phosphors.
So the option to use not only blue but also red and green LEDS in a single light source together with a range of phosphors to spread te energy around exists.
In short you can make an LED lamp have pretty much any spectrum you want, although UV is rather hard
No, they don't. LED spectra are tuneable.
It seems to have driven you insane.
It's so swamped by other consumption here that I can't be arsed to work it out! (current year is about 11,500 kWh).
That's rather like saying a stroke is better than a heart attack. ;-)
You can make reasonably smooth continuous spectrum florries. But not down to a price - and may also be less efficient.
The same happens with LEDs - the better the light quality the less efficient they are. Although are improving.
Andy Burns wrote in news:eag3e4Ffk7hU1 @mid.individual.net:
I think that is "fringing" due to the lens being cheap and not colour corrected (as a camera lens is) Different wavelengths refract differently and give a rainbow fringe.
It is an example of how even well funded, well informed designers can get it wrong.
Guess that someone read something about getting more brightness out by pulsing and missed the rest of the article about average power.
Result being the strobe tail lights fitted to some early LED equipped cars, not got cheep Chinese knock offs to blame either ;-)
Maybe, but it's a lot stronger than the normal chromatic aberration you get from spectacles, I thought it was the blue LED die combined with yellow phosphor?
m, whatever colour they are.
For the purposes of the previous discussion was referring to blue with phos phor white LEDs....
Regretably they certainly aren`t broad.
Efficacy , its proven relatively easy to get more light out of 400nm+ LEDs, splash some phosphor on front, call 6000K white and wham, 100 lumens a Wat t plus!
Lets ignore phosphor degradation , its not good for marketing.
Gets tougher lowering apparent colour temp with phosphor or adding higher w avelength primary emitters.
Amber and red LEDs efficiency isn`t anywhere near as good, need more of the m to balance with lower wavelenghts.
You can , but its not a 1+1+1 combo of desired colours and its still a limi ted palette.
Discharge sources are highly tuneable as well but they rely on the mercury line way down in UV to excite phosphor or metals in mix, LED uses vsible bl ue to excite phosphors.
Back in day was demoed an expensive IIRC Sugden, audio amp, British built, notable feature was of 40W of output about 10W seemed to be permnanent broa dband hiss, was told this was a `feature` of the amp.
White (phosphor) LED has a permanent 460nm ish peak, blue, in it.
RJH pretended :
Me too, but to a lesser extent. I found myself installing higher wattage than needed CFL's, simply to overcome their initial dimness at switch on. Not something LED suffers.
I have replaced all the lights which are in regular use with LED, but left higher wattage CFL's as centre lights, where these are not normally in use, just so we have brighter lighting available when needed. LED's come on instantly at full brightness. Many of our lamps are indistinguishable from ordinary lamps, though some are due to their more limited colour spectrum.
I would compare LED v standard lamps are 1:7 to 1:9 in power saving, but the savings only affect the lighting proportion of your consumption. I have been logging consumption quite carefully over the past year, from September - there was a very noticeable step change to less consumption of around 1/3 less than was used in August. That despite the heating pump running twice a day for HW, laptops running, plus the usual kettle, microwave, TV's and etc.. Plus the darkening evenings.
I have also implemented a trial policy of no larger wattage LED than is needed for lighting an area. I found 3.5W LED's for hall, stairs and landing adequate for normal use, but swapped them temporarily for 22w CFL over the past couple of weeks whilst we were redecorating these areas.
Is there a need to know the proportion? If the question is, how much money will be saved surely all you need to know is how much electricity is consumed by the lighting?
I thought they were a design feature because some people seem to believe it is trendy to have blue lights.
The LED colour rendering isn't quite right but 2700K tungsten lighting is nothing like the natural light from the sun at 5000K. Colour film sees the difference but the human eyes white balance auto adjusts.
Basically the body might need some UV exposure per day for vitamin D synthesis but neither LED *nor* conventional incandescents provide it.
Persistence of vision and long phosphor glow time means that what little flicker there is in LED lamps is negligible. They stay lit a suprisingly long time after switching off. Incandescents also flicker slightly at 100Hz.
This isn't true of some brake lights on cars or pelican crossings which give a really annoying brutal flashing effect in peripheral vision.
That is complete bollocks. The LED luminaires are more tightly controlled than the old lamps which means if designed right there is a lot less sideways glare and more light on the roadway. They do tend to need to be closer together than some old types of street lamp.
The LEDs don't have to get much more efficient/cheaper before it becomes possible to make them spaced the same as HPS/LPS fixtures.
The one criticism that you can make is that because of the very tight control of sideways light spill it becomes more difficult to pick out the future direction of a road lit by LED fixtures. You can really only see them from a distance by the illumination of the supporting pole.
Very little to none at all.
I'm not even shure why they strobe. Not something I've been particularly aware of. Could it be an interaction with some street lighting?
I saw a figure quoted the other day.
It wouldn't be difficult to rig up a house with metering for light only use. Or to calculate it, I suppose.
I was interested to see how much those on here thought they were saving by changing to more efficient lighting. Especially as few have anything good to say about CFL.
I have managed to trim about 5kWh / day off my electrical usage in the period where I phased in LED lighting. Not all of that will be just down to lighting, but I expect most of it will be. However that's not an average setup.
Care to say just how you're measuring that sun? The colour temperature of daylight varies by the time of day and time of year. Even before clouds, etc.
I'd say an LED 'stays lit' because of its power supply. Not intrinsically.
That makes my 4,508 kWh for the last 12 months seem quite frugal.
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